What is a common anti-cholinergic side effect of phenothiazines?

• A. Increased salivation
• B. Blurred vision
• C. Dry mouth
• D. Weight gain

Answer: (C)

Phenothiazines, which are a class of medications commonly used to treat psychiatric disorders such as schizophrenia and as antiemetics, have several side effects that are associated with their anticholinergic properties. One of the most notable anticholinergic side effects is dry mouth.

This occurs because anticholinergic medications block the action of acetylcholine, a neurotransmitter involved in stimulating saliva production. As a result, a person may experience a reduction in saliva, leading to dry mouth, which can also be uncomfortable and increase the risk of dental issues due to reduced oral hygiene.

In contrast, increased salivation is actually opposite to what anticholinergic effects would cause. Blurred vision can occur as a side effect, but it is often more directly related to other side effects of phenothiazines. Weight gain is a possible side effect of various medications but is not specifically an anticholinergic effect of phenothiazines. Therefore, dry mouth is the most commonly recognized anticholinergic effect associated with these drugs, making it the correct and most relevant answer.